碳纳米管填充PTFE的制备及平头型小冲杆测试研究

采用冷压烧结法制备了经过不同表面处理和不同含量多壁碳纳米管(MWCNTs)改性的聚四氟乙烯(PTFE)材料,探索采用平头型小冲杆测试方法对材料进行性能测试。得到了材料的载荷 位移曲线,发现不同的表面处理和不同含量的MWCNTs对聚四氟乙烯复合材料性能具有不同的增强效果。通过对填充材料的扫描电镜（SEM）分析,认为MWCNTs可以导致PTFE材料纤维韧性强化的倾向。     

碳纳米管改性聚四氟乙烯材料的导热性能

针对所制备的由不同表面处理和不同含量的多壁碳纳米管（MWCNTs）填充的聚四氟乙烯（PTFE）复合材料,测定其在变温度场下的导热系数、热扩散系数和热膨胀系数,得到了一系列关系曲线,初步分析了材料的热性能特点和规律。通过分析,发现随填充物含量的增加,由不同表面处理的MWCNTs填充的PTFE材料的导热性能均有所提高,但差异较大;特别是当热源输入温度较高时,导热系数和热扩散系数均显著增加。通过透射电镜(TEM)分析了不同表面处理的MWCNTs在PTFE中的微观结构,预测了在不同温度场下,材料各组分和内部结构对材料热性能的影响规律。     

3种玻璃陶瓷与Wieland Zenostar氧化锆相互摩擦的耐磨性比较

目的：探讨3种玻璃陶瓷与Wieland Zenostar氧化锆（简称Zenostar）相互摩擦的耐磨性差异,阐明其影响因素。方法：Zenostar做成平面型（锆片组）和半球型（锆球组）,3种玻璃陶瓷IPS Empress CAD （简称Empress）、IPS e.max CAD （简称e.max）和VITA Suprinity （简称Suprinity）分别作为其对磨材料,置于UMT-2微摩擦磨损试验机上,在人工唾液环境下进行二体磨损,模拟口腔内使用过程。使用激光共聚焦显微镜检测平面试样的磨损深度,扫描电子显微镜（SEM）观察分析磨损表面。结果：锆片组,3种玻璃陶瓷对Zenostar产生的最大磨损深度比较差异无统计学意义（P>0.05）;锆球组,Zenostar对3种玻璃陶瓷及Zenostar基底样本产生的最大磨损深度由小到大依次为Zenostar组< e.max组≈Empress组< Suprinity组,e.max组与Empress组比较差异无统计学意义（P>0.05）,其余各组间比较差异均有统计学意义（P<0.01）。SEM观察,锆片组中Zenostar磨损表面均较光滑,多为磨粒磨损;锆球组中Empress表面磨损最为严重,可见大面积碎片剥脱面,表面粗糙不平。结论：3种玻璃陶瓷与Zenostar相互摩擦的耐磨性与材料本身组成成分和化学结构有关。     

比较不同长度及表面修饰的多壁碳纳米管的细胞毒性和遗传毒性

目的：比较不同长度和表面修饰的多壁碳纳米管（multi-walled carbon nanotubes,MWCNTs）对人肺泡Ⅱ型上皮细胞（A549细胞）的细胞毒性和遗传毒性的影响。方法：选取长（5~15 μm）、短（350~700 nm）两种不同长度的MWCNTs,及羧基（carboxyl,COOH-）、氨基（amino,NH_2-）和牛磺酸（taurine,Tau-）3种不同表面修饰的MWCNTs分别进行实验研究,其中短的MWCNTs作为未修饰的MWCNTs（Pristine-MWCNTs）与表面修饰的MWCNTs进行比较。细胞毒性实验采用cell counting kit-8（CCK-8）法,染毒浓度为 2、8、32 mg/L,染毒时间分别为12、24、36、48 h;遗传毒性采用单细胞凝胶电泳实验检测DNA链断裂,染毒剂量为8 mg/L,染毒时间24 h。结果：两种长度的MWCNTs在所观察的12~48 h染毒时间内,均表现出剂量依赖的细胞毒性;其中在24~48 h处理时间组,MWCNTs的细胞毒性随长度增加而增大。经过表面修饰的3种MWCNTs与未修饰的MWCNTs相比,表面修饰过的MWCNTs在染毒时间12 h、染毒浓度为32 mg/L时相对细胞活性：COOH-MWCNTs为（86.55±1.80）%、NH_2-MWCNTs 为（84.67±1.32）%、Tau-MWCNTs为（80.15±3.53）%,均高于未修饰MWCNTs的细胞活性（71.44±5.58）%,差异具有统计学意义（P＜0.05）;在染毒时间24 h、染毒浓度为8 mg/L时修饰过的MWCNTs相对细胞活性：COOH MWCNTs 为（96.74±1.00）%、NH_2-MWCNTs为（96.74±3.35）%、Tau-MWCNTs为（106.39±3.83）%,均高于未修饰MWCNTs的细胞活性（91.02±2.53）%,差异具有统计学意义（P＜0.05）;在染毒时间24 h、染毒浓度为32 mg/L时修饰过的MWCNTs相对细胞活性：COOH-MWCNTs为（80.88±2.67）%、NH_2-MWCNTs 为(82.90±3.25)%、Tau-MWCNTs为 (82.55±3.32）%,均高于未修饰MWCNTs的细胞活性（76.08±4.27）%,差异具有统计学意义（P＜0.05）;在染毒时间36 h、染毒浓度为8 mg/L时修饰过的MWCNTs相对细胞活性：COOH-MWCNTs为（96.87±1.05）%、NH_2-MWCNTs为（96.66±4.76）%、Tau-MWCNTs为（100.23±2.84）%,均高于未修饰MWCNTs的细胞活性（89.61±3.78）%,差异具有统计学意义（P＜0.05）。在其他观察时间和染毒浓度下,经过表面修饰的MWCNTs与未修饰MWCNTs的细胞活性相比,差异无统计学意义（P＞0.05）。经过表面修饰的3种MWCNTs DNA链断裂损伤情况：Olive尾距COOH-MWCNTs为1.56±0.22、NH_2-MWCNTs为2.25±1.62、Tau-MWCNTs为2.23±0.94,尾部DNA含量COOH-MWCNTs为（3.96±0.60）%、NH_2-MWCNTs为（6.16±4.68）%、Tau-MWCNTs为（6.05±2.31）%,均在不同程度上低于未修饰的MWCNTs［Olive尾距为3.00±0.64,尾部DNA含量为（8.23±2.27）%］,差异具有统计学意义（P＜0.05）,其中COOH-MWCNTs所致DNA链断裂损伤最小。结论：上述材料在所观察时间和染毒剂量下,均引起了A549细胞不同程度的细胞毒性和DNA链断裂,相同染毒浓度下,不同长度的MWCNTs所致细胞毒性及DNA 链断裂程度有所差别;表面修饰可在一定程度上降低MWCNTs对A549细胞的细胞毒性和DNA链断裂损伤。     

3种冠修复材料与牙釉质磨耗性能的体外研究

目的：通过体外实验比较3种冠修复材料及天然牙釉质的摩擦磨损性能,为临床上选择与天然牙磨耗性能相近的修复材料提供一定实验依据。方法：选取高度抛光的饰面瓷、爱尔创氧化锆、可切削复合树脂材料Lava Ultimate为实验组,对照组为天然牙釉质,以滑石瓷为对磨物,模拟口腔环境,在CFT?Ⅰ型材料表面性能综合测试仪上进行二体摩擦磨损实验,通过检测试样表面粗糙度、表面硬度、磨损量、磨斑形貌,研究天然牙釉质与不同材料之间的摩擦磨损性能。采用单因素方差分析方法进行统计学分析。结果：3种冠修复材料自身磨损量和对磨物磨损量与牙釉质组相比差异均有统计学意义（P < 0.05）,其中Lava Ultimate及对磨物与天然牙釉质及对磨物的磨损量最接近。结论：与饰面瓷对比,氧化锆具有更佳的耐磨性及更低的对磨物磨损;与天然牙釉质相比,Lava Ultimate具有更强的耐磨性及更低的对磨物磨损;与饰面瓷和氧化锆对比,Lava Ultimate的耐磨性能及对磨物磨损等方面与天然牙釉质更为接近。     

聚醚砜耐高温摩阻材料的研究

用热塑性聚(氧-1,4-亚苯基磺酰基-1,4-亚苯基)(聚醚砜)树脂作粘接剂,制备耐高温摩阻材料,探索了材料的压制工艺。试验证实了:聚醚砜树脂和制成的摩阻材料,其耐热性和摩擦磨损性能,较大程度优于改性酚醛树脂和其制成的材料。通过近代表面分析手段对摩擦表面和磨屑进行了分析,并探讨了其磨损机理。     

无石棉摩阻材料的研究

经较详尽的试验对比,钢纤维增强的摩阻材料的摩擦学性能和机械性能,都优于硅酸铝纤维和无碱玻璃纤维增强的材料。提供了利用正交设计法筛选配方的方法,得到优化的半金属摩阻材料的配方。利用近代表面分析工具对半金属摩阻材料的表面和磨屑进行观察分析,并探讨了磨屑的形成机理。     

飞秒激光在钛合金表面改性中的应用及其对成骨细胞黏附和增殖的影响

目的：采用不同能量密度飞秒激光处理钛合金表面,比较其对成骨细胞黏附和增殖的影响,探讨飞秒激光在种植材料表面改性中的作用。方法：钛合金Ti-6Al-4V圆片进行打磨抛光并采用不同能量密度的飞秒激光处理,分为低能量组（0.07 J•cm^-2）和高能量组（1.40 J•cm^-2）,同时以单纯打磨抛光样本为对照组,扫描电镜观察各组材料表面形貌;人成骨样细胞素MG63与各组材料进行共培养,扫描电镜观察材料表面黏附细胞的形态并采用丫啶橙染色和荧光显微镜观察黏附细胞的数量,用噻唑蓝（MTT）比色分析法测定MG63细胞的吸光度（A）值,分析不同时间点细胞增殖率。结果：飞秒激光处理钛合金表面形成2种不同的微形貌结构,即纳米级平行排列的条纹状结构和微米级的凸起与纳米级的条纹相结合的微纳复合结构;24 h各组黏附的细胞数量相近;48 h各组材料表面单个细胞形态均不明显,但微纳复合结构表面细胞覆盖面积大于纳米条纹表面和对照组的光滑表面,高能量组细胞增殖率明显高于对照组和低能量组（P＜0.05）。结论：飞秒激光处理钛合金表面产生的微纳复合结构有利于MG-63成骨细胞黏附和增殖。     

两种生物陶瓷与硅橡胶复合材料的制备及物理性状比较

目的按照不同配比制备适合组织填充的新型双相生物陶瓷硅橡胶复合材料和羟基磷灰石/硅橡胶复合材料,并对材料物理性状进行观察。方法共混法制备不同配比的双相生物陶瓷/硅橡胶材料和羟基磷灰石/硅橡胶复合材料,检测双相生物陶瓷颗粒粒径并与羟基磷灰石颗粒进行对比,对复合材料进行扫描电镜观察。结果制备出了双相生物陶瓷质量配比30、50、70份的复合材料,通过观察,参照物羟基磷灰石颗粒平均粒度40.28μm,双相生物陶瓷颗粒平均粒度为52.28μm。结论双相生物陶瓷颗粒在复合材料内大部分粒径完整,分布均匀,作为生物软组织填充的理想赝复材料,可进行下一步检测。     

新型腹腔化疗管复合材料的制备与性能表征

目的 本研究采用医用硅橡胶经聚四氟乙烯(PTFE)改性,用于制备植入体内的新型腹腔化疗管复合材料.方法 对其材料进行物理机械性能、动物试验安全性进行评价.结果 PTFE添加最对复合材料硬度的影响不大,随着PTFE含量增加,复合材料仍保持较高的物理机械性能;复合材料通过过敏试验、热源试验、全身急性毒性试验表明,所制备的复合材料在生物学评价试验中均呈阴性反应,材料无明显毒性,材料中不存在潜在致敏性物质,所含热原含量符合生物体的要求.具有优良的生物相容性.结论 本文所制备的硅橡胶/PTFE复合材料具有较高的物理机械性能和优良的生物相容性,是制备腹腔化疗导管的良好材料.     

Value of D-Dimers in patients with acute aortic dissection

Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P ＜ 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (＞0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P ＜0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P ＜ 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.     

Research of combined liver-kidney transplantation model in rats

Objective： To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods： SD rats served as both donors and recipients. 4℃ sodium lactate Ringer＇s was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava （IVC） inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results： Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion： This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.     

BLOOD PRESSURE CHANGE WITH AGE IN SALT-SENSITIVE TEENAGERS

Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P＜ 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P＜ 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.     

安心颗粒对急诊经皮冠状动脉介入术后生活质量影响的研究

目的：评价使用安心颗粒对急诊经皮冠状动脉介入术（PPCI）术后生活质量的影响.方法：将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组（术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次）和对照组（仅接受基础药物治疗）.所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表（MIDAS）、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果：入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异（P＞0.05）;出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低（P＜0.05）;组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低（P＜0.05）.两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血（P＞0.05）.两组发生轻度血小板减少症的患者数比较无差异（P＞0.05）.结论：PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.     

The comparative studies of the influences of Urapidil and Nicardipine on sino-atrial node function, atrio-ventricular node function and hemodynamics

Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P＜0.01);the MAP decreased(P＜0.01)and the HR increased drastically(P＜0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.     

Expression of OPGmRNA and ODFmRNA in the patients of hip fracture due to osteoporosis

Objective：To investigate the gene expression of osteoprotegerin（OPG） and osteoclast differentiation factor（ODF） in the bone tissue of patients with hip fracture due to osteoporosis. Methods：OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers（over 50 years old） with hip fracture（Observer Group） and 30 cases of hip facture sufferers with no osteoporosis（Control group） were analyzed with the Semi-Quantitative RT-PCR method. Results：The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion：Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.     

The clinicopathological and immuohistochemical analysis of solid-pseudopapillary tumor of the pancreas： report of 9 cases

Objective：To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas（SPTP）. Methods：Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin（HE） staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results：Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin（9/9 cases）, AAT（9/9 cases）, NSE（9/9 cases）, ACT（7/9 cases）, CK20（2/9 cases）, CgA（1/9 cases）, S-100（3/gcases）, PR（4/gcases）, Syn（3/9 cases） and CD56（5/9cases）, negative in CEA and ER. Conclusion：SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype.     

Dynamic Changes in Serum Estradiol and Progesterone levels in Patients of Premenstrual Syndrome with Adverse Flow of Liver-qi

Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.     

Real-time Three-dimensional Echocardiography in Assessment of Left Ventricular and Right Ventricular Volumes

Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.     

SCREENING FOR A 21-CHROMOSOME ABNORMALITY IN PREIMPLANTED EMBRYOS OF ELDERLY WOMEN

Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.